A predictor-corrector method for solving the diffusion equation for water movement in unsaturated soil PublicDeposited

Descriptions

The study of water movement in unsaturated soils by using appropriate
diffusion equations has attracted considerable attention in
recent years.
In this study, a numerical technique is developed for solving
a generalized, dimensionless diffusion equation by the use of a digital.
computer. Diffusivity and capillary conductivity equations derived
by Brooks and Corey [2] have been used instead of measured data;
thus, the dimensionless diffusion equation can be applied to many
soils and many kinds of fluids.
In this thesis, the diffusion equation has been solved for the
one -dimensional, vertical case, where drainage was permitted from
an initially saturated soil.
Some dimensionless curves of water content distribution in soil
profiles at various selected times are presented. Outflow data calculated
as a function of time is also included. The computer solutions
using the Brooks -Corey approximations seem to fit the experimental
data very well. It therefore seems that the diffusion equation
solved here is a satisfactory model for water movement in unsaturated
soil.
An ALGOL program is included in the Appendix.